Sonntag, 12. November 2017 - 21:15 Uhr

The Near-UltraViolet image of NGC 2336 observed by the UVIT on board the AstroSat. The bright spots along the spiral arms are regions of active star formation. Credits: UVIT Team.

NGC 2336 is a magnificent barred spiral galaxy located in the northern constellation of Camelopardalis, or the giraffe. At a distance of 105 million light years away from us, it can even be seen through medium-sized amateur telescopes under dark skies. This galaxy was discovered by the German astronomer Ernst Tempel in 1877. NGC 2336 has a highly developed and splendid spiral arm structure that emanates from a ring of stars surrounding a central bar. The spiral arms contain a number of star forming regions, or nebulae. These nebulae shine because of hot young stars that are bright in the ultraviolet.

This was one of the first objects chosen to be imaged by the Ultra-Violet Imaging Telescope (UVIT) on board AstroSat, in order to test its ability to resolve complex structure. The Near-UV (200-300 nm) and Far-UV (130-180 nm) images obtained were spectacular, showing details finer than in the image from the GALEX ultraviolet telescope. Astronomers found that the resolution of UVIT was 1.2 arc-seconds in the Near-UV and 1.5 arc-seconds in the Far-UV, which was much better than the initial goal of 1.8 arc-seconds. This superior resolving power, along with its large field of view, make UVIT an excellent instrument for investigating star formation in large galaxies like NGC 2336.

Sonntag, 12. November 2017 - 21:00 Uhr

X-ray polarisation: All types of electromagnetic radiation, like X-rays and optical light, are bundles of energy called photons defined by an electric vector, and an orthogonal magnetic vector. The electric vectors are mostly random in orientation, but quite often, they are aligned to a particular direction depending on the conditions in the source of these photons. For example, optical light scattered in the sky are aligned, or polarised, in the plane of the scattering and you can take a simple optical polariser to look at the sky and determine the direction of the incident photons (prior to scattering) from the source – in this case the Sun. The polarisation properties of electromagnetic radiations have been regularly used by astronomers to study the conditions of the cosmic sources emitting these radiations. For example, the direction of the magnetic field in our galaxy, Milky Way, can be precisely mapped using polarisation measurements.

Strong X-ray emission from astrophysical sources often signifies the presence of exotic compact objects in the universe: neutron stars and black holes. The X-ray emission from these objects traces the regions of particle acceleration and understanding the conditions of particle acceleration can tell us about several exotic phenomena: for instance, whether the black hole is spinning, does the strong gravity near black holes obey Einstein’s equation, or if neutron stars are made up of ordinary matter or strange matter and so on. It has long been thought that X-ray polarisation properties will tell us more about the mysteries of these strange objects.

Immediately after the birth of X-ray astronomy in 1962, due to the serendipitous discovery of an extra-solar X-ray source in a rocket flight, there was a flurry of activity in all aspects of X-ray astronomy, including polarisation measurement. Scientists at Columbia University flew a simple scattering based X-ray polarimeter in a rocket flight in 1969 to look at the pulsar in the Crab Nebula: they could not detect any polarisation – less than 36% of X-ray photons had their electric vectors aligned. They sent another rocket in 1971 with an improved version with graphite crystals to look at X-rays of specific energy at 2.6 keV and discovered X-ray polarisation in Crab: about 20% of the photons at this energy show aligned electric vectors. Buoyed by this success, they sent a polarimeter in the 8th Orbiting Solar Observatory (OSO-8) in 1975: it confirmed the X-ray polarisation in Crab and put quite stringent (5 – 10%) upper limits on the polarisation of several bright X-ray sources.

Exploring X-ray Polarisation using AstroSat

AstroSat, being India’s first dedicated astronomy mission, was a massive effort involving the participation of many ISRO centres, academic institutes, and universities. Tata Institute of Fundamental Research (TIFR), Mumbai led the scientific effort by shouldering the responsibility to deliver three of the five major payloads of AstroSat.

Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, founded for the explicit purpose of promoting “the nucleation and growth of active groups in astronomy and astrophysics at Indian universities’’, was an indirect participant in the AstroSat instrument development: Dipankar Bhattacharya (IUCAA) designed the specialised `coded aperture masks’ for two instruments of AstroSat. Since AstroSat is supposed to be an observatory class satellite catering to all users, including those from the universities, it was thought that a formal participation of IUCAA in several allied tasks like software development, student training, etc. would enhance the utility of AstroSat data.

Arthur Holly Compton had discovered, in 1923, that X-rays can deposit part of their energy in a material and undergo `Compton’ scattering. The CZT detectors are pixellated (and hence, have position information) and at certain energies, X-rays will interact primarily by Compton scattering. If the instrument can be made sensitive to measure the incident X-rays as well as the scattered X-rays, then the distribution of the scattered X-rays in the neighbouring pixels of the CZT detector will show some tell-tale signs of the polarisation properties of the incoming X-rays. Such pixellated X-ray detectors are thought to work as X-ray polarimeters, but experimentally no one, so far, had demonstrated the polarisation properties of pixellated X-ray detectors. Since X-ray polarisation measurement is a long sought after experimental technique in X-ray astronomy, examining the utility of CZTI as an X-ray polarimeter looked attractive.

Polarisation Experiments

There followed a flurry of activity to demonstrate that CZTI can be used as an X-ray polarisation instrument. Rao ascertained from the supplier of the CZT detectors that the properties of incident and scattered X-rays are measured and retained, and this was quickly demonstrated by some simple experiments using radio-active sources of known energies. Santosh used a sophisticated code to simulate this behaviour and satisfied himself that polarisation measurements can indeed be made. Then followed a series of Varkari between Ahmedabad and Mumbai: Santosh and his student Tanmoy Chattopadhyay (currently working as a post-PhD researcher at Pennsylvania State University) made controlled experiments on the flight models of CZTI detectors. Several improvisations were part of the testing: like the use of simple thermocol pieces as experimental set-up, use of very strong radio-active sources of X-rays and making them scatter from blocks of aluminium to polarise them - but using sophisticated simulations to precisely calculate the energy of scattered X-rays.

All these activities were done while the fabrication and testing of the flight models were going on ! First a single X-ray detector, called a module, was bombarded with X-rays of known energies and its properties were measured. A rigorous modelling, based on these experimental results, showed that CZT Imager as a whole, with 64 detector modules, will have enough sensitivity to measure X-ray polarisation from bright cosmic X-ray sources. Then started a series of controlled experiments for the proof of concept: beams of X-rays were generated, with or without polarisation, and the polarisation signal in the detector was measured and compared with the results from the simulations. All the tests were repeated for X-rays of a single energy, as well as continuum of X-rays (as expected from Cosmic X-ray sources). Finally, some precious time was readjusted from the very tight delivery schedule of the flight model to repeat these tests in a fully flight-like environment.

This is only the beginning of the story. Because, all the tests in the lab are made with small beams of X-rays and in flight, while observing X-ray source situated at thousands of light years away, one expects parallel beam of polarised X-rays. To test with similar large area polarised beam of X-rays in the lab, one needed to build a humongous facility – perhaps taking several years of effort just to fabricate it. The whole detector geometry was simulated and sophisticated simulations were carried out to predict the behaviour of the detector. These were compared with the controlled lab experiments of small beam, at different experimental configurations, to satisfy that the simulation results are indeed as observed in the lab. This gave a confidence for the prediction of the parallel beam of large area and the results indeed showed that CZT Imager is a very sensitive X-ray polarimeter.

Finally, on 2015 September 28, a fully ground calibrated X-ray polarimeter was flown into space.

The special source ‘Crab’ and its polarisation

When a new era of astronomy was ushered in by telescopes in the 17th and 18th century Europe, it was realised that the sky consists of several fuzzy objects, apart from point-like stars, and they were named ‘Nebula’. The Crab Nebula, in the constellation of Taurus, is the first object identified by Messier, a French astronomer, who meticulously catalogued such objects. Crab Nebula cannot be seen by the naked eye, but can be seen as a fuzzy crab-like feature (hence the name) by a simple binocular. Among such nebulae, supernova remnants form a large fraction. Soon, it was realised that the Crab Nebula is none other than the `Guest Star’, or the supernova recorded by the Chinese astronomers in year 1054.

Within a year of the discovery of pulsars (rapidly rotating highly magnetised neutron stars) in 1967, a pulsar with a period of 33 milliseconds was discovered in the Crab Nebula. It was, however, surmised that the explosion of the supernova that occurred about 1000 years ago has long lost its energy and currently, the nebula is powered by the monster sitting at its centre: the fast spinning neutron star. Crab Nebula, along with its pulsar, became the darling of all observers: it is the only pulsar observed to be pulsating in all branches of the electromagnetic radiation, from radio to even ultra high energy gamma-rays. Since the pulsations are due to simple light-house effect of the rotating neutron star, the period should be, and indeed is, the same in all wavelengths - hence the Crab pulsar became a calibrating source to test the timing accuracy of any new window of observation. The emission mechanism is understood as due to the movement of particles in a magnetic field, the particles being accelerated to humongous energies in the polar cap of the highly rotating magnetic neutron star. Since the magnetic field and the rotation period are reasonably stable for several years, the emitted flux, in hard X-rays, is expected to be a constant : hence it also became a good flux calibrator for any new observations. The realisation that particles are accelerated to very high energies has made a strong case for such young supernova remnants as sources of the mysterious particles bombarding the Earth: Cosmic Rays.

In recent years, Crab Nebula and pulsar are the subjects of diverse observations and theorising to understand the particle acceleration mechanism in fast spinning neutron stars. Measurement of polarisation as a function of pulse phase in optical and radio wavelengths and detailed theoretical modelling are hinting that particle acceleration happens outside the `light-cylinder’ of this source and scientists across the globe are pondering over the nature of such acceleration

Crab polarisation using AstroSat

Crab Nebula was the first source AstroSat stared at post switch ON and verification, and, it kept looking at this source quite often for a periodic calibration of the X-ray instruments, as well as to measure its polarisation. There followed a very meticulous analysis. Every recorded photon was examined, stringent criteria were imposed on them to be validated as `Compton-scattered’ events, their distribution among their neighbours were examined, for consistency, among different detectors in the instrument. Regions in the sky were identified and the position of the satellite was manoeuvred such that the instrument looks at a `source-free’ region in the sky at similar satellite orientation with respect to Earth. The behaviour of the detector was studied in these `background’ regions and the resultant profile was subtracted from the source observations. To establish that these `Compton-scattered’ photons were really from Crab, their arrival times were investigated and found to be beating at the standard Crab clock of 33 milli-seconds.

Yes, X-ray polarisation was clearly detected even in individual observations lasting about half a day and when all the eleven observations were added together, the measurement is clearly the most precise hard X-ray polarisation measurements till date The results were submitted to the British journal Nature.

It is true that measuring polarisation with the highest accuracy possible is a technical challenge: but what is the new thing we are learning ? After a few weeks of intense debate among the researchers, it was decided to collect more data and attempt a very precise measurement of the variation of the polarisation properties when the pulsar beam sweeps across us, the observers. For this, data from different observations spanning across 18 months had to be added. Do we know the pulsar period accurately for this ? The Crab pulsar was observed in radio wavelengths from the Ooty radio telescope every day and also many times during these months from the Giant Meter-wave Radio Telescope (GMRT) at Khodad, near Pune. The pulse of pulsar was accurately measured, the X-ray photons were assigned a pulse phase and the change in the polarisation property as a function of the pulsed beam emission was studied.

When we think that the pulsar beam is shining elsewhere, the remainder of the beam has sufficient X-ray emission, with the polarisation increasing and also showing a sharp change. What it means is that the light house is leaking and emitting high energy X-rays all the time. Most magnetospheric theories predict that the polarisation of X-ray radiation will show changes only during the emission of a pulse, but not at other times. The new observations thus support the view that the particle acceleration is happening outside the conventional boundary of the magnetosphere, in a region where the charged particles generated by the pulsar are spiralling out in the form of a wind. The surprising observation by CZTI of a sharp change of polarisation in the “off pulse” region is clearly a big challenge to theorists.

Left panel: The grey line shows the brightness of the Crab pulsar as observed by AstroSat CZTI. The horizontal axis (phase) represents time expressed in units of the pulsar’s spin period. Phase 0.0 to 1.0 stands for the full rotation cycle of the pulsar. The same result is shown repeated between phase 1.0 and 2.0, for a clear demonstration of the periodic pattern. Colored bars indicate how strongly polarized the observed radiation is. Sharp variation of polarization when the brightness is low is the surprising discovery by AstroSat.

Right panel: The angle of X-ray polarization measured by AstroSat CZTI shown superposed on a composite optical and X-ray image of the Crab nebula, taken by NASA’s Hubble and Chandra telescopes respectively. The white arrow represents the projected spin axis of the pulsar located at the center of the nebula. Other arrows display the orientation of the observed polarization. The color of an arrow indicates the range of phase it belongs to, being equal to that spanned by bars of the corresponding shade in the left panel.

Sonntag, 12. November 2017 - 19:00 Uhr

The NASA-funded FOXSI instrument captured new evidence of small solar flares, called nanoflares, during its December 2014 flight on a suborbital sounding rocket. Nanoflares could help explain why the Sun's atmosphere, the corona, is so much hotter than the surface. Here, FOXSI's observations of hard X-rays are shown in blue, superimposed over a soft X-ray image of the Sun from JAXA and NASA's Hinode solar-observing satellite.

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Like most solar sounding rockets, the second flight of the FOXSI instrument - short for Focusing Optics X-ray Solar Imager - lasted 15 minutes, with just six minutes of data collection. But in that short time, the cutting-edge instrument found the best evidence to date of a phenomenon scientists have been seeking for years: signatures of tiny solar flares that could help explain the mysterious extreme heating of the Sun's outer atmosphere.

FOXSI detected a type of light called hard X-rays - whose wavelengths are much shorter than the light humans can see - which is a signature of extremely hot solar material, around 18 million degrees Fahrenheit. These kinds of temperatures are generally produced in solar flares, powerful bursts of energy. But in this case, there was no observable solar flare, meaning the hot material was most likely produced by a series of solar flares so small that they were undetectable from Earth: nanoflares. The results were published Oct. 9, 2017, in Nature Astronomy.

"The key to this result is the sensitivity in hard X-ray measurements," said Shin-nosuke Ishikawa, a solar physicist at the Japan Aerospace Exploration Agency, or JAXA, and lead author on the study. "Past hard X-ray instruments could not detect quiet active regions, and combination of new technologies enables us to investigate quiet active regions by hard X-rays for the first time."

These observations are a step toward understanding the coronal heating problem, which is how scientists refer to the extraordinarily - and unexpectedly - high temperatures in the Sun's outer atmosphere, the corona. The corona is hundreds to thousands of times hotter than the Sun's visible surface, the photosphere. Because the Sun produces heat at its core, this runs counter to what one would initially expect: normally the layer closest to a source of heat, the Sun's surface, in this case, would have a higher temperature than the more distant atmosphere.

"If you've got a stove and you take your hand farther away, you don't expect to feel hotter than when you were close," said Lindsay Glesener, project manager for FOXSI-2 at the University of Minnesota and an author on the study.

The cause of these counterintuitively high temperatures is an outstanding question in solar physics. One possible solution to the coronal heating problem is the constant eruption of tiny solar flares in the solar atmosphere, so small that they can't be directly detected. In aggregate, these nanoflares could produce enough heat to raise the temperature of the corona to the millions of degrees that we observe.

One of the consequences of nanoflares would be pockets of superheated plasma. Plasma at these temperatures emits light in hard X-rays, which are notoriously difficult to detect. For instance, NASA's RHESSI satellite - short for Reuven Ramaty High Energy Solar Spectroscopic Imager - launched in 2002, uses an indirect technique to measure hard X-rays, limiting how precisely we can pinpoint the location of superheated plasma. But with the cutting-edge optics available now, FOXSI was able to use a technique called direct focusing that can keep track of where the hard X-rays originate on the Sun.

"It's really a completely transformative way of making this type of measurement," said Glesener. "Even just on a sounding rocket experiment looking at the Sun for about six minutes, we had much better sensitivity than a spacecraft with indirect imaging."

FOXSI's measurements - along with additional X-ray data from the JAXA and NASA Hinode solar observatory - allow the team to say with certainty that the hard X-rays came from a specific region on the Sun that did not have any detectable larger solar flares, leaving nanoflares as the only likely instigator.

"This is a proof of existence for these kinds of events," said Steve Christe, the project scientist for FOXSI at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and an author on the study. "There's basically no other way for these X-rays to be produced, except by plasma at around 10 million degrees Celsius [18 million degrees Fahrenheit]. This points to these small energy releases happening all the time, and if they exist, they should be contributing to coronal heating."

There are still questions to be answered, like: How much heat do nanoflares actually release into the corona?

"This particular observation doesn't tell us exactly how much it contributes to coronal heating," said Christe. "To fully solve the coronal heating problem, they would need to be happening everywhere, even outside of the region observed here."

Hoping to build up a more complete picture of nanoflares and their contribution to coronal heating, Glesener is leading a team to launch a third iteration of the FOXSI instrument on a sounding rocket in summer 2018. This version of FOXSI will use new hardware to eliminate much of the background noise that the instrument sees, allowing for even more precise measurements.

A team led by Christe was also selected to undertake a concept study developing the FOXSI instrument for a possible spaceflight as part of the NASA Small Explorers program.

Sonntag, 12. November 2017 - 14:30 Uhr

The third transportation vehicle for NASA’s Commercial Resupply Services 2 contracts for resupply efforts of the International Space Station has passed a major ground test milestone at Edwards Air Force Base, California. Completing a 60 mph (96.5 k/h) tow test earlier this month, Sierra Nevada Corporation’s Dream Chaser mini-spaceplane is now aiming for a series of Captive Carry flight tests suspended underneath a 234-UT lifting commercial helicopter.

Initially, NASA was expected to award only two CRS-2 contracts; however, the agency formally announced in January 2016 that three companies would be awarded contracts – including Sierra Nevada for Dream Chaser alongside current CRS-1 contract holders SpaceX and Orbital ATK.

Since arriving at Edwards earlier this year, Dream Chaser’s refurbished ETA has been used to validate numerous ground processing activities on the vehicle and has recently completed a major milestone test.

That test saw Sierra Nevada engineers hook Dream Chaser up to a separable towing mechanism to allow the team to gather data on stresses and responses on the vehicle to various towing speeds as well as its final landing elements (i.e., how it decelerates in its final moments of landing).

During the test earlier this month, a pickup truck towed Dream Chaser’s ETA to a total speed of 60 mph (96.5 k/h), performing several s-curve ground turns before initiating a release of the tow mechanism to allow Dream Chaser to slow to a stop on its skid strip and tires.

Now, teams are preparing for a series of two Captive Carry tests ahead of the free flight Approach and Landing Test 2 (ALT-2) for Dream Chaser.

Moreover, the helicopter that will be used for both Captive Carry tests and for ALT-2, arrived at Edwards Air Force Base in mid-August and is very different from the one used in 2013.

That helicopter was an ERICKSON S-64F. The new copter is a 234-UT lifting helicopter – the civilian version of the CH-47 Chinook.

The 234-UT is capable of lifting 11,793 kg (26,000 lb) and of attaining a cruise speed of 120 kts (222 k/h – 138 mph) – something that will aide Sierra Nevada in their desire to use ALT-2 to send Dream Chaser through a more robust flight environment on her short, one minute flight from altitude to the runway.

But before ALT-2, the 234-UT will lift Dream Chaser to altitude, performing two Captive Carry test.

During the Captive Carry tests, Dream Chaser will be suspended below the 234-UT while the helicopter flies a pattern at various altitudes within the perimeter of Edwards Air Force Base.

“One of the primary objectives of the first Captive Carry test is to verify and validate the performance of the ETA Guidance Navigation and Control systems and to exercise operations of the ETA under the control of the flight control team while in an actual flight-like operational environment,” notes the L2 update.

If those two Captive Carry test are successful, Sierra Nevada will move on to ALT-2 at the end of September.

Currently, if funding levels and schedules hold, Sierra Nevada anticipates the first cargo Dream Chaser flight to the ISS in 2020.

The current CRS-2 contracts grant Sierra Nevada, SpaceX, and Orbital ATK six flights each for resupply services to and from the Station – for a total of 18 commercial cargo runs between 2019 and 2024.

Under the CRS-2 contract, Dream Chaser will provide a total cargo uplift capability on each flight of 5,000 kg (11,000 lb) of pressurized cargo and 500 kg (1,100 lb) of unpressurized cargo – with a recoverable downmass cargo capability of 1,750 kg (3,860 lbs) and a disposable cargo capability of 3,250 kg (7,170 lb).

Moreover, Dream Chaser has been selected by the United Nations to fly uncrewed microgravity science missions for nations that don’t have domestic access to space (the first of which is expected No Earlier Than 2021), and the Trump Administration in the United States is understood to be studying a proposal set forth by Sierra Nevada to use of Dream Chaser for a crewed servicing mission to the Hubble Space Telescope in the 2020s.

The Dream Chaser engineering test article, slung underneath a civilian variant of the Chinook helicopter, took off here at 10:21 a.m. Eastern. It landed at 12:02 p.m. Eastern, with the company declaring the flight a success.

During the test, SNC collected data on the vehicle’s performance in flight, including operation of radar altimeters, air data probes and other systems that cannot be fully tested on the ground. The captive carry test followed a series of tow tests here in recent months, where the vehicle was towed behind a truck down a runway at speeds of up to 100 kilometers per hour.

“It went as good as we could possibly expect,” said Steve Lindsey, vice president of space exploration systems for SNC, during a briefing here after the completion of the flight. “From what we saw in real time, everything was working exactly as expected.”

This captive carry flight is one of the final steps before a free flight, where Dream Chaser will be carried aloft by the helicopter and released to make a runway landing. That glide flight is the remaining funded milestone in the company’s Commercial Crew Integrated Capability (CCiCap) Space Act Agreement with NASA that the agency awarded in August 2012.

A second captive carry flight, expected to take place in about a month, will incorporate lessons learned from this flight, the company said. That will be followed by a free flight test before the end of the year.

Dream Chaser has performed one glide flight previously, in October 2013, as part of an earlier Commercial Crew Development award. The vehicle landed on the runway here but skidded off when part of its main landing gear collapsed. The vehicle did not suffer significant damage, and both the company and NASA considered the flight a success.

The vehicle that flew on its captive carry flight is the same as the one used for the 2013 tests, after repairs and upgrades. The vehicle now has the same avionics system that the company plans to use on its orbital vehicle, Lindsey said.

This flight also allowed the helicopter pilots to familiarize themselves with carrying the Dream Chaser. This flight used a different model of helicopter as the earlier series of flights. “For the helicopter pilots, it was a learning curve for them, learning how to get our vehicle into the drop box,” the airspace location where the vehicle would be released on a glide flight, he said. “They did a great job.”

SNC developed Dream Chaser to transport astronauts to and from the ISS. However, NASA instead selected proposals from Boeing and SpaceX in September 2014 for full-scale development of those vehicles. SNC filed a protest with the U.S. Government Accountability Office about that decision, but the GAO rejected the protest in January 2015.

The company has since been focused on development of a version of the vehicle to transport cargo. NASA awarded SNC a Commercial Resupply Services (CRS) 2 contract in January 2016, joining existing cargo providers Orbital ATK and SpaceX and guaranteeing the company at least six cargo missions between 2019 and 2024. The cargo version is similar to the crew version, but includes a separate module attached to the rear of the vehicle to carry additional cargo.

SNC announced July 19 it signed a contract with United Launch Alliance for the first two launches of Dream Chaser cargo spacecraft on Atlas 5 552 rockets. The first launch is scheduled for 2020 and the second in 2021, although Lindsey said that NASA has not formally ordered any Dream Chaser flights under its CRS-2 contract yet.

While SNC is focused for now on developing the cargo version of Dream Chaser, the company has not closed the door on developing a crew version. Lindsey said the company recently signed a five-year unfunded extension of its CCiCap agreement with NASA to support potential future development of a crewed vehicle.

“We have some unfunded milestones where NASA will come in and look at our requirements and how we’re developing our cargo vehicle, look at the path or trace to the crewed vehicle, and help us out,” he said of the extended agreement with NASA.

“We’re going to do cargo first, and do the best we can with cargo and prove out the vehicle,” he said, “but our intent some day is to go back to crew as well. How and when is TBD.”

Quelle:SN

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Dream Chaser completes aerial captive carry test flight

About one-quarter the length of a space shuttle orbiter, the Dream Chaser is being developed to ferry cargo to and from the International Space Station. After blasting off on time of an Atlas 5 rocket, the ship will return to land on a runway.

The automated spacecraft was lifted airborne Wednesday by a dual-rotor Boeing Vertol 234 helicopter operated by Columbia Helicopters. The “captive carry” test flight was expected to be used to test out telemetry and control systems before a planned drop test later this year to demonstrate Dream Chaser’s ability to make an autopilot approach and landing to a runway.

The captive carry test comes after a series of tow tests at NASA’s Armstrong facility, co-located at Edwards Air Force Base in California’s Mojave Desert.

Sierra Nevada plans the first orbital flight of Dream Chaser to the space station in 2020.

Suspended under a 200-foot lift line, the 30-foot-long (9-meter) test craft flew around the dry lake bed at Edwards Air Force Base, making several high-speed and high-altitude passes to test out the ship’s aerodynamics and simulate the conditions needed during the approach and landing demonstration later this year.

“On-board the vehicle, we have all the orbital vehicle avionics,” said Steve Lindsey, senior director and co-program manager for Sierra Nevada’s space exploration systems division. “The avionics on-board are identical to what we will have on the orbital vehicle, as well as the flight software for the orbital vehicle.

“That’s why (this test) is so critical to us,” said Lindsey, a former space shuttle commander. “It will test that. It will also test the aerodynamics of the vehicle. We flew it once before and know kind of how it flies, but we’re going to test that again and get additional aerodynamic data.”

Credit: Sierra Nevada Corp.

Sierra Nevada webcast the start of the test live, but the company ended the video stream shortly after takeoff. The vehicle made a safe landing after about an hour-and-a-half airborne.

“We are very pleased with results from the captive carry test, and everything we have seen points to a successful test with useful data for the next round of testing,” said Lee Archambault, a former astronaut and Sierra Nevada’s director of flight operations for the Dream Chaser program.

The current testing in California comes four years after Sierra Nevada conducted similar flight tests when the company aimed to fly Dream Chaser with astronauts on-board. The Dream Chaser test vehicle made an on-target approach to a runway after letting go from its helicopter carrier, but one of the craft’s main landing gear failed to deploy, leading the spaceplane to spin out of control after touchdown.

Sierra Nevada says the 2013 flight was successful until that point, and Dream Chaser’s autopilot landing system steered the craft toward the runway for a touchdown on the centerline.

Engineers blamed the mishap on a landing gear borrowed from a U.S. Air Force F-5E jet. Future Dream Chaser cargo missions to the space station will fly with a different landing gear, and the refurbished spaceship now in California features a gear more advanced then the one at fault in 2013.

Engineers also upgraded the ship’s computer systems to be more like the orbital version of the Dream Chaser.

At least one more captive carry test is planned before the free flight, which Lindsey said must be conducted in cooler weather than the scorching temperatures Wednesday in the Mojave Desert. The carrier helicopter’s lift capability is limited by hot temperatures.

Sierra Nevada also plans a release test using airbags before the Dream Chaser’s approach and landing flight to check out the drop mechanism.

Quelle: SN

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The SNC Mission Control Center team sent commands to Dream Chaser, monitored performance and collected critical test data designed to allow the team to refine Dream Chaser systems for peak performance on the actual Free Flight test day.

WASHINGTON — Sierra Nevada Corporation is expected to perform a second glide test of its Dream Chaser vehicle as soon as next week, according to comments from a NASA official.

Bill Gerstenmaier, NASA associate administrator for human exploration and operations, said at a House Science Committee hearing Nov. 9 that the glide flight of the uncrewed vehicle, at Edwards Air Force Base in California, was planned for Nov. 14.

“They have a drop test on the 14th of this month to look at their vehicle coming back,” he said when asked about the company’s work by Rep. Ed Perlmutter (D-Colo.) at the hearing.

A company, in a statement to SpaceNews, didn’t confirm the date Gerstenmaier provided during the hearing, but said that preparations for the glide flight are continuing. “We are still on schedule for a free-flight test this year,” the company said, with the timing depending on factors such as availability of helicopters used to support the test as well as access to NASA and Air Force facilities.

The glide flight will be the second for this vehicle, an engineering test article originally developed as part of Sierra Nevada Corp.’s commercial crew activities. On the first flight, in October 2013, a helicopter released the Dream Chaser at an altitude of about 3,600 meters, allowing it to glide to a runway landing at Edwards.

The test, though, was marred by the failure of one of the vehicle’s landing gears to deploy, causing it to skid off the runway after touchdown. The vehicle suffered only minor damage, though, and both NASA and the company considered the test flight a success.

Sierra Nevada Corp. shipped the Dream Chaser, after repairs and other modifications, to NASA’s Armstrong Flight Research Center at Edwards early this year for testing leading up to a second glide flight. That flight will be the final funded milestone on the company’s Commercial Crew Integrated Capability award made by NASA in 2012.

The company performed a captive carry flight Aug. 30 at Edwards, carrying the vehicle aloft under a helicopter for nearly two hours. That test was performed with media present and broadcast on NASA TV. A second captive carry test, without outside coverage, took place about a month later.

While Sierra Nevada Corp. failed to win a commercial crew contract, which NASA awarded to Boeing and SpaceX in 2014, it subsequently won a Commercial Resupply Services 2 cargo contract with NASA, along with Orbital ATK and SpaceX, using a version of Dream Chaser. The company’s first two cargo missions are planned for 2020 and 2021, launching on a United Launch Alliance Atlas 5.

Quelle: SN

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Update: 12.11.2017

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SNC’s Dream Chaser Achieves Successful Free Flight at NASA Armstrong

Sierra Nevada Corp’s Dream Chaser lands on Edwards Air Force Base in California. Spacecraft went through preparations for flight at NASA’s Armstrong Flight Research Center.

Credits: NASA / Carla Thomas

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Sierra Nevada Corp.’s Dream Chaser spacecraft underwent a successful free-flight test on November 11, 2017 at NASA’s Armstrong Flight Research Center, Edwards, California. The test verified and validated the performance of the Dream Chaser in the critical final approach and landing phase of flight, meeting expected models for a future return from the International Space Station.

The flight test helped advance the vehicle under NASA’s Commercial Crew Program space act agreement, as well as helped prepare the vehicle for service under NASA’s Commercial Resupply Services 2 program. The testing will validate the aerodynamic properties, flight software and control system performance of the Dream Chaser.

The Dream Chaser is preparing to deliver cargo to the International Space Station beginning in 2019. The data that SNC gathered from this test campaign will help influence and inform the final design of the cargo Dream Chaser, which will fly at least six cargo delivery missions to and from the space station by 2024.

On the heels of Orbital ATK’s successful OA-7 Cygnus cargo run, teams at Virginia’s Wallops Flight Facility are preparing for the OA-8E mission. The 139-foot (42.5-meter) tall Antares rocket is slated to take an enhanced Cygnus and several tons of science and cargo to the International Space Station on Sept. 12, 2017.

Kurt Eberly, the program manager for Antares, said that the company would have OA-8E ready to travel as early as late July and certainly in August if necessary. Regardless of when it does get off the ground, the mission will send 7,385 pounds (3,350 kilograms) of cargo packed inside an enhanced Cygnus spacecraft. Liftoff will take place from Pad 0A at Wallops Island, Virginia.

The OA-8E mission is part of the Commercial Resupply Services (CRS) 1 contract. The “E” signifies the CRS-1 contract extension, enabling NASA to cover space station resupply needs until the CRS-2 contract begins in 2019. Orbital ATK was awarded at least three additional Cygnus flights. SpaceX was also awarded additional flights.

After OA-8E will be OA-9E, which is currently scheduled to launch in March 2018 atop an Antares 230 rocket. The Antares rockets for both of these missions can be seen in the company’s horizontal integration facility.

The last Cygnus mission, OA-7, launched atop an Atlas V rocket from Cape Canaveral, Florida. While the spacecraft can be sent to space using either launch vehicle, there are currently no more plans for Orbital ATK to use the Atlas V.

Eberly said that by improving the performance of Antares, utilizing the pair of RD-181 engines, Orbital ATK is expected to achieve 13 percent higher thrust with 10 seconds of additional specific impulse (ISP). This should net 20–25 percent more mass to be delivered to orbit resulting in increased payload delivered to the ISS.

It is expected that, by OA-11E, Orbital ATK should be able to achieve its designed mass of 7,716 pounds (3,500 kilograms) of cargo and probably beyond in the CRS-2 missions.

For Antares’ second stage, there is a large Castor 30XL motor which is manufactured by the Propulsion Systems Division of Orbital ATK located in Utah.

Dale Nash, executive director at the Mid-Atlantic Regional Spaceport (MARS) on Wallops Island, indicated that Pad 0A should be ready for OA-8E by end of July.

Nash briefed the media that with the last Antares launch, in October 2016, the rocket lifted off quickly and, as a result, there was much less damage to the launch pad, thereby improving turnaround times between launches to about 30 days.

“Wallops has a fairly wide open azimuth between 38 to 60 degrees inclination which the ISS is right in the sweet spot for that,” Nash said, talking about the advantages of Wallops over Cape Canaveral. Additionally, he said that there are far fewer scheduling conflicts at the Wallops Flight Facility and less chance of getting bumped.

Moreover, improvements to the design of Cygnus itself, including strengthened internal infrastructure and an improved power supply, allows for better support of science payloads. Additionally, procedural protocols allowing for later cargo insertion into the Cygnus have proven to have significant advantages allowing for easier accommodation of NASA cargo requests.

Quelle: SpaceFlight Insider

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Update: 7.10.2017

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NASA Offers Access to Cygnus Spacecraft Ahead of Next Space Station Mission

Media are invited to view and photograph Orbital ATK’s Cygnus spacecraft, packed with cargo and scientific experiments for its upcoming flight to the International Space Station.

Media are invited to view and photograph Orbital ATK’s Cygnus spacecraft, packed with cargo and scientific experiments for its upcoming flight to the International Space Station, at 10:30 a.m. EDT Wednesday, Oct. 18, at NASA’s Wallops Flight Facility on Wallops Island, Virginia.

Media also will have an opportunity to speak with NASA and Orbital ATK officials about the targeted no earlier than Nov. 10 mission and the space agency’s effort to send supplies to the space station using commercial companies. The officials available at the event include:

To attend this event, media must apply for accreditation by contacting Keith Koehler at keith.a.koehler@nasa.gov by noon, Tuesday, Oct. 17. Accreditation is open only to media who are U.S. citizens.

Orbital ATK will make its eighth Cygnus cargo delivery to the International Space Station under its commercial resupply services contract with NASA. The resupply mission will launch on the company’s Antares rocket from the Mid-Atlantic Regional Spaceport’s Pad 0A at Wallops.

Following the Cygnus viewing, media will have the opportunity to visit the upgraded Wallops Range Control Center.

Quelle: NASA

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Update: 11.10.2017

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Mission Update: OA-8 Space Station Cargo Resupply

Orbital ATK’s Cygnus spacecraft is scheduled to launch aboard an Antares launch vehicle for the sixth time from NASA’s Wallops Flight Facility in Virginia on November 10, 2017. Cygnus will deliver vital equipment, supplies and scientific equipment to the space station as part of Orbital ATK’s Commercial Resupply Services (CRS) contract with NASA.

Designed to provide responsive and low-cost access to space, Antares is a two-stage vehicle (with optional third stage) that provides low-Earth orbit (LEO) launch capability for payloads weighing up to 8,000 kg. Internally funded by Orbital ATK, Antares completed a risk reduction mission and a demonstration of commercial re-supply services for the International Space Station (ISS) under a NASA Commercial Orbital Transportation Services (COTS) agreement in 2013. Orbital ATK commenced delivery of cargo to the ISS under the NASA Commercial Resupply Services (CRS) contract in 2014.

About Cygnus

Cargo is delivered to the station using Orbital ATK’s Cygnus spacecraft. The Cygnus spacecraft consists of two modules: the Service Module (SM) which incorporates the avionics, propulsion and power systems from Orbital ATK’s flight proven LEOStar and GEOStar spacecraft buses; and the Pressurized Cargo Module (PCM) which carries the crew supplies, spares and scientific experiments. The SM is integrated and tested at Orbital ATK’s Dulles, Virginia satellite manufacturing facility. The PCM is supplied by Thales Alenia Space and is produced in Turin Italy.

Quelle: Orbital ATK

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Update: 21.10.2017

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S.S. Gene Cernan: Space station resupply ship named for late moonwalker

Orbital ATK has named its next space station-bound Cygnus cargo ship the S.S. Gene Cernan after the late moonwalker. (Orbital ATK)

October 18, 2017

— The last human to step off the moon is the latest astronaut to be memorialized with the naming of a space station-bound cargo ship.

Gene Cernan, who commanded NASA's final Apollo moon landing mission in 1972, died at the age of 82 in January. Orbital ATK's next Cygnus commercial resupply spacecraft to launch honors Cernan's commitment to exploration and discovery.

"Today we announced that we're naming the OA-8 vehicle after Gene Cernan. It is the 'S.S. Gene Cernan,'" said Rick Mastracchio, Orbital ATK senior director of operations for the Commercial Resupply Services program and a former NASA astronaut, on Wednesday (Oct. 18).

"[Eugene] Cernan's role in the development of America's space program ushered in a new era of human spaceflight that continues to make new scientific discoveries through the International Space Station." Orbital ATK described in a fact sheet posted to its website.

The S.S. Gene Cernan is targeted to lift off Nov. 11 aboard an Orbital ATK Antares 230 booster from the Mid-Atlantic Regional Spaceport at the NASA Wallops Flight Facility in Virginia. After arriving and being berthed to the station, the orbiting lab's crew will unpack the Cygnus of its cargo and, for the first time, use it to extend their science work areas.

The Cygnus spacecraft will be outfitted with TangoLab, a reconfigurable general microgravity research facility. "This exercise will demonstrate the ability to expand the station's capabilities for hosting experiments," stated Orbital ATK.

The S.S. Gene Cernan will remain connected to the station for two weeks and then will depart to deploy 14 cubesats (small satellites), more than any prior mission. The Cygnus module will then perform a destructive re-entry into Earth's atmosphere over the Pacific Ocean.

The flight of the Gene Cernan will mark the ninth Cygnus to be launched to resupply the International Space Station under a contract with NASA. Of the eight missions to date, all but one was successful.

The naming of the Cygnus continues a company tradition to name Orbital ATK's (formerly Orbital Sciences) missions for individuals who made contributions to the program. All of the Cygnus ships have been christened for astronauts.

Earlier Cygnus vehicles were named for astronauts David Low, Gordon Fullerton, Janice Voss, Deke Slayton (twice, including a Cygnus destroyed in a 2014 launch failure) and Rick Husband.

In addition to being the last human to step off the moon's surface (to date), Cernan was the second U.S. astronaut to walk in space and one of only three people to fly to the moon twice. A veteran of three missions (Gemini 9, Apollo 10 and Apollo 17), Cernan logged more than 23 days in space, with more than 73 hours on the lunar surface.

The mission patch for the S.S. Gene Cernan (also referred to as OA-8) includes the NASA astronaut symbol as part of its design in reference of the late astronaut.

International Space Station U.S. National Lab Payloads Prepped for Orbital ATK CRS-8 Launch

The Orbital ATK Cygnus vehicle is slated to launch to the International Space Station (ISS) no earlier than November 11, 2017 from Wallops Flight Facility. The Cygnus spacecraft will carry a dozen ISS National Laboratory payloads to conduct research across a variety of areas aimed at improving life on Earth. In addition to the diverse research launching to the ISS National Lab, multiple payloads focused on enabling future research missions will be part of the CRS-8 manifest. Thus far in 2017, the ISS National Lab has sponsored more than 100 separate experiments that have reached the station.

Below highlights ISS National Lab sponsored investigations as part of the Orbital ATK CRS-8 mission:

This project was developed by the Higher Orbits Go for Launch! student competition Orbital ATK Division winning team, the Saguaro Snakes (Gilbert, AZ). The project is focused on establishing a baseline for plant growth in extraterrestrial colonies. Microclover, a resilient and drought-tolerant legume will be grown in microgravity to determine the effect of the space environment on the nitrogen-fixation process and micro-green growth. Insight gained from this experiment could be useful in ongoing efforts to create a self-sufficient greenhouse in microgravity, which would necessitate a soil nitrogen source for exploratory purposes.Hardware Partner: Space Tango

The Cost-effective High E-Frequency Satellite (CHEFSat) tests and prepares consumer communications technology for use in space. The growing range of devices, components, and miniaturized technology available in the consumer market represents a boon for space exploration and cost management. CHEFSat seeks to validate a consumer-grade radio frequency device for wider space use by testing its safety and effectiveness in a working CubeSat deployed from the ISS.Hardware Partner: NanoRacks

The E. coli AntiMicrobial Satellite (EcAMSat) investigation seeks to determine the lowest dose of antibiotic needed to inhibit growth of Escherichia coli (E. coli), a bacterial pathogen that causes infections in humans and animals. The experiment will expose wild-type (naturally occurring in nature) and mutant strains of E. coli to three different antibiotic concentrations and then examine the viability of each group using a dye that reveals metabolic activity. As the first mission in the 6U satellite platform configuration, EcAMSat also serves to demonstrate the capabilities of this technology. EcAMSat is being developed through a partnership between NASA’s Ames Research Center with support from the NASA Space Life and Physical Sciences Research and Applications Program and the Stanford University School of Medicine.Hardware Partner: NanoRacks

The Effects of Microgravity on the Life Cycle of Tenebrio Molitor (Tenebrio Molitor) experiment aboard the ISS investigates how the microgravity environment of space affects the mealworm life cycle. Mealworms represent good test subjects because they are well-studied organisms. An automated laboratory apparatus images mealworm growth from larval to adult life stages and then returns samples to Earth based labs for more detailed analysis. This project was conceived by the Higher Orbits AIAA Division winning team – Operation Galaxy X (Herndon, VA).Hardware Partner: Space Tango

The Integrated Solar Array and Reflectarray Antenna (ISARA) prepares a new hybrid antenna and power system for space applications by demonstrating its use in CubeSat-based environmental monitoring. Advances in material science and electrical engineering have made possible a flexible solar panel that can send and receive messages. ISARA tests the performance of these new solar antennas in collecting instrumental data aboard a CubeSat deployed from the ISS and monitored by ground-based engineering crews.Hardware Partner: NanoRacks

The Life Cycle of Arabidopsis thaliana in Microgravity (Arabidopsis thaliana) project studies the morphology and physiology of a common plant species using specialized modular growth chambers aboard the ISS. The plant under investigation grows from germinated seeds under automated light, temperature and nutrient conditions. Automated cameras image growth at every stage to determine both plant viability and the effectiveness of cultivation modules, which return to Earth for further post-mission analysis.Hardware Partner: Space Tango

About 90 percent of global trade is shipped by sea; however, tracking of oceangoing ships is inefficient and many ships are unmonitored as they transit the world’s oceans, far from land and out of range of ground-based beacons. The NanoRacks-LEMUR-2 satellites are part of a remote sensing satellite constellation that provides global ship tracking and weather monitoring. The satellites in this investigation are deployed from both the ISS and the visiting space vehicle, demonstrating the technology at a range of altitude bands.Hardware Partner: NanoRacks

The Optical Communication and Sensor Demonstration (OCSD) will test specific functions of laser-based communications using automated CubeSats deployed from the ISS. Optical communication (communication using lasers) is a next-generation technology that improves the distance, accuracy, and speed of communication in space and in space-to-ground applications. OCSD readies a compact version of this technology for space by demonstrating accurate high-speed optical communication between two small satellites working closely together in low Earth orbit.Hardware Partner: NanoRacks

PROPCUBE-Fauna uses a CubeSat platform to collect critical data for improving communications systems. Both Earth- and space-based communications systems use the outer electrical field of the Earth’s atmosphere to transmit, bend, or bounce message signals. PROPCUBE-Fauna will perform high-resolution measurements on the exact position, density, and potential vibration of this field to transmit signals in a more effective manner.Hardware Partner: NanoRacks

This set of STaARS experiments will be conducted in a new facility on the ISS, the NEXUS Lab, which was designed and built by SpacePharma. Dr. Wallace will be completing a two-part experiment that began on SpaceX CRS-12 involving Staphylococcus aureus (a common skin pathogen). Her experiment examines microgravity-induced molecular alterations that cause S. aureus to change color from its normal gold to clear and that cause the bacteria to lose pathogenicity. By elucidating the mechanisms within S. aureus that change during growth in microgravity, this research could to lead to drug discovery and new therapies. This investigation also serves as a validation study for the NEXUS lab, which seeks to provide researchers with another reliable option for life science research on the ISS.Hardware Partners: SpacePharma and STaARS

The National Geographic Channel–Virtual Reality Educational Video for Television Series “One Strange Rock” will transport a virtual reality camera to the ISS to record a National Geographic special on the Earth as a natural life-support system. Crew onboard the ISS will record a series of virtual reality pieces for incorporation into a larger documentary about the natural history of the Earth and the solar system. Each episode features a different crew member and uses next-generation virtual reality technology to address different topics related to our planet and the space program.Hardware Partner: NanoRacks

This launch manifest adds to an impressive list of experiments from previous missions in 2017 including research in the areas of stem cells, cell culturing, protein crystal growth, external platform payloads, Earth observation, and remote sensing as well as student experiments. To learn more about these investigations and other space station research, visit www.spacestationresearch.com.

# # #

About CASIS: The Center for Advancement of Science in Space (CASIS) is the non-profit organization selected to manage the ISS National Laboratory with a focus on enabling a new era of space research to improve life on Earth. In this innovative role, CASIS promotes and brokers a diverse range of research in life sciences, physical sciences, remote sensing, technology development, and education.

Since 2011, the ISS National Lab portfolio has included hundreds of novel research projects spanning multiple scientific disciplines, all with the intention of benefitting life on Earth. Working together with NASA, CASIS aims to advance the nation’s leadership in commercial space, pursue groundbreaking science not possible on Earth, and leverage the space station to inspire the next generation.

About the ISS National Laboratory: In 2005, Congress designated the U.S. portion of the International Space Station as the nation’s newest national laboratory to maximize its use for improving life on Earth, promoting collaboration among diverse users, and advancing STEM education. This unique laboratory environment is available for use by other U.S. government agencies and by academic and private institutions, providing access to the permanent microgravity setting, vantage point in low Earth orbit, and varied environments of space.

Quelle: CASIS

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Update: 6.11.2017

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Orbital ATK’s S.S. Gene Cernan to Deliver Supplies to Space Station

EcAMSAT, undergoes thermal vacuum power management testing at NASA Ames. The test simulates the thermal vacuum and power environment of space and is an element of the spacecraft's flight validation testing program.

Credits: NASA

The Optical Communications and Sensor Demonstration (OCSD) project uses CubeSats to test new types of technology in Earth's orbit. This work was funded by NASA’s Small Spacecraft Technology Program under the Space Technology Mission Directorate.

Credits: NASA/Ames Research Center

Orbital ATK will launch its Cygnus spacecraft into orbit to the International Space Station, targeted for November 11, 2017, from Wallops Flight Facility in Virginia. Cygnus will launch on an Antares rocket carrying crew supplies, equipment and scientific research to crewmembers aboard the station. The spacecraft, named the S.S. Gene Cernan after former NASA astronaut Eugene “Gene” Cernan, who is the last person to have walked on the moon, will deliver scientific investigations including those that will study communication and navigation, microbiology, animal biology and plant biology.

Here are some highlights of research that will be delivered to the station:

Investigation tests bacterial antibiotic resistance in microgravity

Antibiotic resistance could pose a danger to astronauts, especially since microgravity has been shown to weaken human immune response. E. coli AntiMicrobial Satellite (EcAMSat) will study microgravity’s effect on bacterial antibiotic resistance. The experiment will expose two strains of E. coli, one with a resistance gene, the other without, to three different doses of antibiotics, then examine the viability of each group. Results from this investigation could contribute to determining appropriate antibiotic dosages to protect astronaut health during long-duration human spaceflight and help us understand how antibiotic effectiveness may change as a function of stress on Earth.

CubeSat used as a laser communication technology testbed

Traditional laser communication systems use transmitters that are far too large for small spacecraft. The Optical Communication Sensor Demonstration (OCSD) tests the functionality of laser-based communications using CubeSats that provide a compact version of the technology. Results from OCSD could lead to significantly enhanced communication speeds between space and Earth and a better understanding of laser communication between small satellites in low-Earth orbit.

As space exploration increases, so will the need for improved power and communication technologies. The Integrated Solar Array and Reflectarray Antenna (ISARA), a hybrid solar power panel and communication solar antenna that can send and receive messages, tests the use of this technology in CubeSat-based environmental monitoring. ISARA may provide a solution for sending and receiving information to and from faraway destinations, both on Earth and in space.

Nitrogen fixation process tested in microgravity environment

The Biological Nitrogen Fixation in Microgravity via Rhizobium-Legume Symbiosis (Biological Nitrogen Fixation) investigation examines how low-gravity conditions affect the nitrogen fixation process of Microclover, a resilient and drought tolerant legume. The nitrogen fixation process, a process by which nitrogen in the atmosphere is converted into a usable form for living organisms, is a crucial element of any ecosystem necessary for most types of plant growth. This investigation could provide information on the space viability of the legume’s ability to use and recycle nutrients and give researchers a better understanding of this plant’s potential uses on Earth.

Life cycle of alternative protein source studied

Mealworms are high in nutrients and one of the most common sources of alternative protein in developing countries. The Effects of Microgravity on the Life Cycle of Tenebrio Molitor (Tenebrio Molitor) investigation studies how the microgravity environment affects the mealworm life cycle. In addition to alternative protein research, this investigation will provide information about animal growth under unique conditions.

Investigation studies advances in plant and crop growth in space

The Life Cycle of Arabidopsis thaliana in Microgravity investigation studies the formation and functionality of the Arabidopsis thaliana, a mustard plant with a well-known genome that makes it ideal for research, in microgravity conditions. The results from this investigation will contribute to an understanding of plant and crop growth in space, a vital aspect to long-term spaceflight missions.

The Biological Nitrogen Fixation and Tenebrio Molitor are student investigations in the Go for Launch! - Higher Orbits program and sponsored by Space Tango and the ISS National Lab, which is managed by the Center for the Advancement of Science in Space (CASIS). The Arabidopsis thaliana investigation, also a student investigation, is a part of the Magnitude.io program, sponsored by Space Tango and CASIS.

OA-8 marks Orbital ATK’s eighth cargo delivery mission to the space station, and the research on board will join many other investigations currently happening aboard the orbiting laboratory. Follow @ISS_Research for more information about the science happening on station.

Quelle: NASA

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Update: 7.11.2017

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NASA TV Coverage Set for Next Resupply Mission to International Space Station

NASA commercial cargo provider Orbital ATK is scheduled to launch its eighth mission to the International Space Station at 7:37 a.m. EST Saturday, Nov. 11 NASA’s Wallops Flight Facility in Virginia. Live launch coverage will begin at 7 a.m. on NASA Television and the agency’s website.

NASA TV also will air two prelaunch briefings Friday, Nov. 10. At 11 a.m. mission managers will provide an overview and status of launch operations, and at 3 p.m. scientists and researchers will discuss some of the investigations and technology demonstrations to be delivered to the station.

The Cygnus cargo spacecraft will launch on Orbital ATK’s upgraded Antares rocket from Pad 0A of Virginia Space’s Mid-Atlantic Regional Spaceport, located at Wallops. Following launch on Nov. 11, NASA TV coverage of the spacecraft’s solar array deployment will begin at 9 a.m. and a post-launch news briefing will held at approximately 10 a.m.

Under NASA’s Commercial Resupply Services contract, Cygnus will carry about 7,400 pounds of crew supplies and hardware to the space station, including science and research in support of dozens of research investigations that will occur during Expeditions 53 and 54.

Cygnus will carry several CubeSats that will conduct a variety of missions, from technology demonstrations of laser communication and increased data downlink rates to an investigation to study spaceflight effects on bacterial antibiotic resistance. Other experiments will advance biological monitoring aboard the station and look at various elements of plant growth in microgravity that may help inform plant cultivation strategies for future long-term space missions. The spacecraft will also transport a virtual reality camera to record a National Geographic educational special on Earth as a natural life-support system.

Cygnus will arrive at the station on Monday, Nov. 13. Expedition 53 Flight Engineers Paolo Nespoli of ESA (European Space Agency) and Randy Bresnik of NASA will use the space station’s robotic arm to capture Cygnus at about 5:40 a.m. NASA TV coverage of rendezvous and capture will begin at 4:15 a.m.

After Canadarm2 captures Cygnus, ground commands will be sent to guide the station’s robotic arm as it rotates and attaches the spacecraft to the bottom of the station’s Unity module. Coverage of installation will begin at 7 a.m.

Cygnus will remain at the space station until Dec. 4, when the spacecraft will depart the station and deploy several CubeSate before its fiery reentry into Earth’s atmosphere as it disposes of several tons of trash.

This Cygnus spacecraft is named in honor of the former astronaut Eugene “Gene” Cernan, the last human to step foot on the Moon during the Apollo 17 mission. Cernan set records for both lunar surface extravehicular activities and longest time in lunar orbit. He died in January 2017.

Quelle: NASA

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Update: 10.11.2017

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Antares rocket rolled to Virginia launch pad for station cargo run

A commercial Antares rocket rolled out of a hangar on a one-mile trip to its launch pad on Virginia’s Eastern Shore on Thursday, ready for final countdown preparations ahead of liftoff Saturday morning on a cargo delivery flight to the International Space Station.

The two-stage Antares launcher, assembled and operated by Orbital ATK, emerged from its horizontal integration building at NASA’s Wallops Flight Facility in the predawn hours Thursday. A self-propelled transporter carried the rocket on a mile-long trip south to launch pad 0A, a complex owned by the Virginia Commercial Space Flight Authority, a state agency chartered to attract commercial space business to the region.

The rocket rolled out in steady rain at the spaceport, and the Antares second stage and payload shroud were protected by a weather shield for the approximately two-hour transfer.

Ground crews engaged hydraulic cylinders to lift the 139-foot-tall (42.5-meter) rocket vertical at pad 0A later Thursday. Technicians then began connecting propellant and other fluid lines between the launch pad and the Antares booster.

Orbital ATK’s automated Cygnus spaceship, christened the S.S. Gene Cernan after the late moonwalker, is fastened on top of the Antares rocket with approximately 7,385 pounds (3,350 kilograms) of cargo and supplies for the space station and its six-person crew.

There is a 95 percent chance of favorable weather for Saturday’s launch attempt, and officials said sub-freezing temperatures expected overnight before launch should not be a problem.

Temperatures are forecast to be between 25 and 30 degrees Fahrenheit at launch time Saturday, above the 20-degree limit for an Antares launch.

Climate-controlled air routed through ducts leading into the Antares rocket will ensure the Cygnus spacecraft, its engines and avionics remain within acceptable temperature and humidity constraints. Three environmental control umbilicals will blow air into the Antares payload fairing, the intertank section between the first stage’s liquid oxygen and kerosene tanks, and into the booster’s aft bay.

“Those three volumes, we keep them nice and cozy in cold weather, and we keep them cool in hot weather, and that enables us to launch in a variety of conditions,” said Kurt Eberly, Orbital ATK’s Antares program manager, in a Facebook Live event Thursday previewing the flight.

“Aside from those cold temperatures … the rest of the key conditions look really excellent,” Eberly said. “The winds are benign, they’re from a good direction coming from the north. Upper level winds look pretty calm as well.”

The launch team will load around 41,000 gallons (155,000 liters) of liquid oxygen and 21,000 gallons (79,000 liters) of rocket-grade kerosene into the Antares first stage beginning around 1 hour, 35 minutes before liftoff.

Saturday’s blastoff will be the eighth time Orbital ATK has launched a resupply mission to the space station. Orbital ATK has used its own Antares rocket launched from Virginia four times — with one launch failure in 2014 — and contracted with United Launch Alliance for three Atlas 5 flights from Cape Canaveral.

Liftoff of the commercial resupply mission, named OA-8, scheduled for 7:37:25 a.m. EST (1237:25 GMT) Saturday to begin the Antares rocket’s seven-minute climb into orbit, kicking off its pursuit of the space station. There’s a five-minute launch window available Saturday.

Two kerosene-fueled RD-181 engines, made in Russia and derived from engines used on Zenit and Atlas 5 rockets, will power the Antares’ Ukrainian-built first stage booster, combining to generate around 864,000 pounds of thrust. Shutdown of the RD-181 engines is planned for T+plus 3 minutes, 34 seconds, followed by first stage separation around six seconds later.

The launch Saturday will be the second Antares mission using RD-181 engines, which Orbital ATK ordered from the Russian engine-builder NPO Energomash to replace decades-old Russian-built AJ26 engines blamed for an Antares rocket crash seconds after liftoff in October 2014.

The RD-181 engines performed better than predicted on an Antares launch in October 2016, giving engineers confidence to loosen performance limits for the OA-8 launch. The engines produce more thrust than the AJ26s, and they will be programmed to fire around five seconds longer on Saturday’s launch than on the last Antares flight.

“We flew to a delta velocity threshold,” Eberly said in a press briefing earlier this year. “When we hit that, we shut down the engines. We had a lot of fuel left in the tanks. Now, we’re just going to move that threshold a little higher and burn more of the fuel in the first stage. At that point in the flight regime, the acceleration is pretty high because the stage is pretty light. Most of the propellant is gone, so you actually pick up quite a bit of performance by burning just a few more seconds into that propellant residual in the tanks.”

With the higher performance, the upgraded Antares can carry approximately 300 pounds more cargo than managers initially expected. The lifting of additional conservative flight constraints, coupled with further minor changes to the vehicle, will further raise the Antares rocket’s payload capacity another 300 pounds in the coming years.

Once the first stage finished its job on Saturday’s launch the Antares rocket’s payload shroud will jettison in two halves at T+plus 4 minutes, 11 seconds. The launcher’s Castor 30XL solid-fueled upper stage will ignite at T+plus 4 minutes, 23 seconds, and burn out at T+plus 7 minutes, 6 seconds, delivering the Cygnus cargo ship to an elliptical orbit less than 200 miles (300 kilometers) above Earth.

Deployment of the Cygnus supply carrier is set for T+plus 9 minutes, 3 seconds.

The spacecraft’s two cymbal-shaped electricity-generating solar arrays will unfurl in a fan-like motion around 90 minutes into the mission, and the ship’s thrusters will begin fine-tuning its approach to the space station with a series of course-correction burns Saturday and Sunday.

The Cygnus spacecraft will make a laser-guided final approach to the orbiting research lab Monday, closing to a distance of around 30 feet (10 meters) from the station. European Space Agency astronaut Paolo Nespoli, assisted by station commander Randy Bresnik, will take control of the lab’s Canadian-built robotic arm to capture the Cygnus.

The arm will attach it to a port on the station’s Unity module, where it will stay until around Dec. 4. Astronauts will unpack experiments and supplies hauled inside the Cygnus’ pressurized module, made by Thales Alenia Space in Italy, then load it with trash and other items marked for disposal.

Payloads slated for delivery to the station on the OA-8 mission include food, clothing and a multitude of research experiments.

The Cygnus spacecraft will raise its orbit to around 300 miles (500 kilometers) after departing the station in early December to release a slew of commercial and NASA-developed CubeSats, then the ship will brake out of orbit with the help of thrusters for a destructive re-entry over the South Pacific Ocean.

Quelle: SN

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Wallops Launch Visibility Map - Orbital ATK CRS-8

This map shows the visibility of the upcoming launch of Orbital ATK's CRS-8 mission from Wallops Flight Facility in Virginia, with numeric values indicating the time (in seconds) after liftoff the Antares rocket and Cygnus spacecraft may be visible.

The launch of @OrbitalATK’s #Antares rocket carrying the #Cygnus cargo spacecraft has scrubbed for Saturday after an aircraft was detected in the vicinity of the launch pad. The next launch attempt is set for Sunday, Nov. 12 at 7:14am ET. Details: https://www.nasa.gov/orbital

Sonntag, 12. November 2017 - 10:00 Uhr

A prototype rover is commanded to drive in and sample a quarry resembling a lunar site. The image shows a virtual reality impression of the test.

The rover is a key element of the ESA-led Heracles mission in cooperation with the Canadian Space Agency CSA and Japan’s JAXA space agency.

Heracles is studying the potential of human–robot partnerships for exploring the Solar System, beginning with the still-unexplored far side of the Moon. Astronauts tele-operating the rover from lunar orbit will help to select better, more pristine samples to return to Earth.

The test took place in mid-October at St Alphons de Granby quarry in Quebec, Canada. The site was chosen for its Moon-like landscape.

HERACLES

HERACLES is an ESA-led mission architecture study, which aims for the next steps in lunar exploration. Realising human-robotic partnership, or the interaction between crew and automated systems, is one of the main objective in this study. The mission architecture consists of multiple elements, including a lander, an ascend stage, a sample container and a rover. The elements are described in further detail in the kick-off presentation. The first surface mission is aimed for 2024, starting with the launch of the ascend stage to a station in cis-lunar orbit where a crew will be present. The second launch takes the landing stage carrying a rover on-board.

At the station, the landing stage will dock to the ascend stage after which the combined HERACLES spacecraft will initiate the journey to the lunar surface and land on a site on the far-side of the Moon. On the surface, the rover - containing a sample container - will be collecting samples. The rover will have both: an autonomous mode, and a mode in which it interacts with the crew that performs tele-operations.

The rover stores the samples in the sample container, and drives the container back to the ascend stage which launches toward the station in cis-lunar orbit. Once it arrives at the station, the crew retrieves the sample container, stores it inside the human-rated vehicle, and returns with it to Earth.

These operations will repeat for multiple cycles, and refurbishment missions are needed to transport new landing stages to the station. The ascend stage is re-used for the next mission cycles, and prepares the next steps for future human missions to the lunar surface - making the overall scenario more affordable.

Sonntag, 12. November 2017 - 09:30 Uhr

A Full Moon is a sight to behold on or off planet. ESA astronaut Paolo Nespoli didn’t miss the chance to photograph this one.

Taken from the International Space Station – its solar panels take up much of the frame – the Moon still manages to draw the eye.

After more than 40 years, the Moon is once again in the spotlight of space agencies worldwide, as a destination for both robotic missions and human explorers.

Why now? Relying on the success of the International Space Station partnership, the space community sees the Moon as a springboard to continue human exploration of the Solar System, with Mars as the next goal.

Samstag, 11. November 2017 - 23:00 Uhr

Puerto Rico's Massive Telescope Is Still Running on Generators

The Arecibo Observatory is facing months of costly repairs after Hurricane Maria struck in September.

Nearly two months after Hurricane Maria struck Puerto Rico, many residents are still without power and struggling to get access to water, food, and basic services. This week, a failed transmission line knocked out what little of the island’s electrical grid had been restored, temporarily leaving thousands of people in the dark once again.

The recovery from the devastating Category 4 hurricane is expected to be long and costly for all of Puerto Rico, including at the Arecibo Observatory, the world’s second-largest radio telescope, which sits in a mountain range in the island’s northwest.

As the storm approached Puerto Rico in September, several researchers remained at Arecibo to keep watch over the 305-meter-wide dish, taking shelter in concrete buildings with food, water, and fuel for generators. The staff made it through unharmed, and when the worst of Hurricane Maria passed, they found the facility had survived, with some damage. The main dish, while intact, lost some of its reflective panels, and most of a 29-meter-long antenna was destroyed. But it wasn’t as bad as they expected, considering Hurricane Maria’s 155-mile-per-hour winds. “It’s a thing to be thankful for,” Joan Schmelz, the observatory’s deputy director, toldScience magazine back then.

The observatory was back up and running on generators a week after the hurricane hit. But as of this week, Arecibo still hasn’t resumed normal operations. The observatory is still running on generator power, according to Suraiya Farukhi, a spokesperson for the Universities Space-Research Association (USRA), one of Arecibo’s operators.

Right now, the radio telescope is locked in a single direction, a configuration meant to save energy, Science reports. Maneuvers to point the telescope in different spots would double fuel consumption, and fuel is in high demand on the island.

Arecibo has observed the skies since the 1960s, searching for stars, exoplanets, asteroids, and potential signals from extraterrestrial civilizations. The iconic observatory has served as a research base for, among others, Jill Tarter, the cofounder of the ET-searching SETI Institute; Frank Drake, the creator of the famous equation for estimating the number of potential alien civilizations; and the late Carl Sagan, perhaps the best-known advocate for space exploration. In 1993, astronomers won a Nobel Prize in physics for discovering of a new kind of pulsar—a fast-rotating star that emits beams of light—using the Arecibo dish. The observatory employed the fictional scientist Ellie Arroway in 1997’s Contact, a character inspired by Tarter.

“The lab is in the process now of a complete rebuild that might take a few weeks or even months.”

Some worry the expensive repairs necessary to return Arecibo to normal may influence the National Science Foundation’s thinking on the observatory’s future. NSF, which owns Arecibo, has long considered reducing its annual contributions to the facility and even passing off management to another party. The NSF spends $8.3 million on operations each year, with NASA providing $3.6 million, according to Science. The National Science Board, which governs the NSF, is expected to publicly announce plans for Arecibo’s future next week.

One of the research facilities at Arecibo, the Planetary Habitability Laboratory, which is managed by the University of Puerto Rico, said the lab sustained “extensive damage to its walls, floor, computers, materials, and furniture” and is asking for help in rebuilding. “The lab is in the process now of a complete rebuild that might take a few weeks or even months,” a post on the laboratory’s website said Thursday. “Most of the structural damage to the lab should be covered by FEMA, the insurance, and the university. However, about $14,000 of damage to our furniture, computers, and scientific materials might not be covered.”

The scientists who work at Arecibo face their own personal recoveries. USRA saidthis week that it had shipped from Maryland to Puerto Rico 20 portable generators and donated them to USRA employees who badly need electricity in their homes.

Several employees who hunkered down at Arecibo during the hurricane, tweetingvarious updates—from the state of the observatory to the kinds of snacks they’d brought with them—continue to share news on social media. Their messages highlight the incredibly slow pace of recovery. “And, lo! Our water supply was restored!” Robert Minchin, head of radio astronomy at Arecibo, tweetedWednesday, seven weeks after the hurricane arrived. “This morning I have water, power, and broadband at home!” he wrote a day later.

Samstag, 11. November 2017 - 18:00 Uhr

– A solid gold model of NASA's Apollo lunar module is now up for auction, as one of the only two others in existence remains missing after a museum heist.

Astronaut Buzz Aldrin's gold scale model of the spacecraft that he and Neil Armstrong piloted to the first moon landing in July 1969, promptly exceeded its opening bid of $10,000 at RR Auction's space memorabilia sale on Thursday (Nov. 9). The Boston-based firm expects that the Cartier-crafted model will command $150,000 or more by the close of the auction on Nov. 16.

"Intricately reproducing the iconic lunar module in solid [18 karat] gold and presented to one of the first humans on the moon, this is a spectacular piece of the utmost rarity," said Bobby Livingston, executive vice president at RR Auction.

The French jeweler Cartier was commissioned to produce the three gold lunar modules by the newspaper "Le Figaro" for presentation to Apollo 11 crew of Armstrong, Aldrin and Michael Collins during the astronauts' post-mission visit to Paris in October 1969. Le Figaro invited its readers to help underwrite the models' creation and they gave generously.

The names of the newspaper's supporters and subscribers were listed on microfilm rolls that were hidden inside each of the models, secreted under the descent stage engine. A plaque affixed to the front of each model also notes that is it a gift from "Les lecteurs du journal Le Figaro" (in English, "Readers of the newspaper Le Figaro").

Armstrong's model was displayed at the Armstrong Air and Space Museum in Wapakoneta, Ohio – the late astronaut's hometown – until July of this year, when a thief absconded with it, as well as several awards and medals that were on exhibit alongside the model. To date, the artifacts have not been recovered.

Aldrin divested of his gold model some time ago and he is not directly involved in its present sale. At some point in its history, Aldrin's model was separated from its red leather, pyramidal case and sustained some damage. A few pieces of the lunar module are missing, including an ascent stage support post, supporting brackets near the ladder, and the antennas on top. The model also exhibits some tarnishing to its golden finish.

Cartier has told RR Auction it is willing to restore the lunar module at its Paris facility at the winning bidder's expense.

Cartier has offered to restore Buzz Aldrin's lunar module model for the winning bidder, at the buyer's expense. (RR Auction)

"The moon landing is one of the greatest achievements of mankind. This Cartier model pays tribute to the bravery of the Apollo 11 astronauts," stated Livingston.

RR's sale, which features the space memorabilia collection of the late inventor of the aftermarket air conditioner for the Volkswagen Beetle in 1969, includes some 20 other lots of Apollo 11 mementos among the 200 total items. One of the highlights is a page from the mission's flown Lunar Module Activation Checklist, with Armstrong's notations listing the steps to prepare for undocking with the command module Columbia prior to the lunar landing.

Also for sale are letters from Collins and Aldrin, including a 1976 note from the latter describing the view on the moon as "very stark and absolutely without any color, just black and shades of gray."